Apparently pins P0.26 & P0.27 for the nRF51822 are by default used for the 32kHz crystal. These we used for SPI communications, so again we had to solder bypass connectors. Pins P0.28 & P0.29 worked great instead.

We did not connect VCCIO from the ADXL362 accelerometer near C6 capacitor, hence another bypass was required.

So we got our boards manufactured and delivered just before the weekend. We decided to visit our local fablab in Lodz to have enough space and non-disturbed time to get this over with. Unfortunately time flies and we only managed to solder one 9+DOF board and a few smaller ones with MS5611, MS5803 and BMP280 pressure sensors.

nRF51822 board fits perfectly, but we also found a flaw on our PCB. Seems like double checking board design isn't enough. The W25Q256FV Eagle layout we found somewhere on the internet does not match the physical part. We haven't soldered this component and will have to make bypass connectors. :-/

While waiting for PCB manufacture we decided to move on. We 3D printed previously designed cases and were surprised they fit together quite nicely. Obviously the rough edges had to be ground with a sandpaper and a small file, but hey ... 10 years ago this would not be possible in a garage :-)

Our print profile used in Repetier 3D printing software can be found here.

Finally we routed the board. This is the first time we designed a PCB so please forgive any blunders. Managed to squeeze all 3 SPI sockets for potential extensions like pressure sensors. We can already think of some crazy applications.

We also have sockets for battery and buzzer connections. This way there is no need to solder anything, just plug&play.

So ... the wheels are turning. We have done the electrical schematics for the board. All measurement components (accelerometer, 9DOF and expansion slots) have been put on SPI1 lane, whereas both FLASH and FRAM memories have been separated onto SPI2. Let's hope we can find room to fit three SPI1 expansion slots for additional sensors.